Skeletal muscle lipid content and insulin resistance: Evidence for a paradox in endurance-trained athletes
Skeletal muscle lipid content and insulin resistance: Evidence for a paradox in endurance-trained athletes
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DOI：
10.1210/jc.86.12.5755
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发表时间：
2001-12-01
影响因子：
5.8
通讯作者：
Kelley, DE
中科院分区：
文献类型：
--
作者：
Goodpaster, BH;He, J;Kelley, DE
我们研究了这一假设，即过量积累的肌内脂质（IMCL）与胰岛素抵抗，这可能是由肌肉的氧化能力介导的。9名久坐不动的瘦型（L）和11名肥胖（O）受试者，8名患有2型糖尿病的肥胖受试者（D）和9名瘦型、运动训练（T）受试者自愿参加本研究。在高胰岛素血症（40 mU .m（-2）min（-1））正葡萄糖钳夹过程中测定的L和T的胰岛素敏感性（M）高于O和D（9.45 +/- 0.59和10.26 +/- 0.78 vs. 5.51 +/- 0.61和1.15 +/- 0.83 mg . min（-1）kg去脂质量（-1））。通过油红O染色定量图像分析，经皮股外侧肌活检标本中的IMCL在D组比L组高约2倍（3.04 +/- 0.39 vs. 1.40 +/- 0.28%脂质面积; P < 0.01）。IMCL在T组（2.36 ± 0.37）也高于L组（P < 0.01）。肌纤维琥珀酸脱氢酶染色测定的肌肉氧化能力在T组高于L、O和D组（分别为50.0 +/- 4.4、36.1 +/- 4.4、29.7 +/- 3.8和33.4 +/- 4.7光密度单位; P < 0.01）。当排除接受过药物治疗训练的受试者后，IMCL与M呈负相关（r =-0.57，P < 0.05），且这种相关性与体重指数无关。然而，IMCL和M之间的关系并不显着时，受过训练的个人。非糖尿病患者氧化能力与M呈正相关（r = 0.37，P < 0.05）。总之，训练有素的耐力运动员的骨骼肌是显着的胰岛素敏感性，并具有高氧化能力，尽管具有较高的脂质含量。总之，脂质氧化的能力可能是一个重要的调解人之间的关联，过量的肌肉脂质积累和胰岛素抵抗。
We examined the hypothesis that an excess accumulation of intramuscular lipid (IMCL) is associated with insulin resistance and that this may be mediated by the oxidative capacity of muscle. Nine sedentary lean (L) and 11 obese (O) subjects, 8 obese subjects with type 2 diabetes mellitus (D), and 9 lean, exercise-trained (T) subjects volunteered for this study. Insulin sensitivity (M) determined during a hyperinsulinemic (40 mU .m(-2)min(-1)) euglycemic clamp was greater (P < 0.01) in L and T, compared with O and D (9.45 +/- 0.59 and 10.26 +/- 0.78 vs. 5.51 +/- 0.61 and 1.15 +/- 0.83 mg . min(-1)kg fat free mass(-1), respectively). IMCL in percutaneous vastus lateralis biopsy specimens by quantitative image analysis of Oil Red O staining was approximately 2-fold higher in D than in L (3.04 +/- 0.39 vs. 1.40 +/- 0.28% area as lipid; P < 0.01). IMCL was also higher in T (2.36 +/- 0.37), compared with L (P < 0.01). The oxidative capacity of muscle determined with succinate dehydrogenase staining of muscle fibers was higher in T, compared with L, O, and D (50.0 +/- 4.4, 36.1 +/- 4.4, 29.7 +/- 3.8, and 33.4 +/- 4.7 optical density units, respectively; P < 0.01). IMCL was negatively associated with M (r = -0.57, P < 0.05) when endurance-trained subjects were excluded from the analysis, and this association was independent of body mass index. However, the relationship between IMCL and M was not significant when trained individuals were included. There was a positive association between the oxidative capacity and M among non-diabetics (r = 0.37, P < 0.05). In summary, skeletal muscle of trained endurance athletes is markedly insulin sensitive and has a high oxidative capacity, despite having an elevated lipid content. In conclusion, the capacity for lipid oxidation may be an important mediator of the association between excess muscle lipid accumulation and insulin resistance.